Friction-clutch.



No. 699,447. Patented may s, |992.

M. CAMPBELL. FRICTIUN CLUTCH.

(Application led Dec. 16, 1901.) (No Model.) Z'Sheeis-Sheet l.

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Patented may s, |902.

M. CAMPBELL.

FRIGTION CLUTCH.

(Application filed Dec. 16, 1901,)

2 Sheets-Sheet 2.

(No Model.)

UNrrhiD STATES MALCOLM CAMPBELL, OF BOSTON, MASSACHUSETTS.

PATENT Ormes.

FRICTlo'N-cLuTcl-l.

SPEGXFLCATION forming part of Letters Patent No. 699,447, dated May 6, 1902.

' Application led December 16, 1901. Serial No. 86,051. (No model) Worm and worm-Wheel for transmitting move-V ment to said shoes to force them into operative position. The said clutch also provided mechanism for positively locking the Worm to the rotating clutch member to cause its rotation and the consequent actuation of the oppositely-movable shoes. I have found it to be difficult in some cases to positively clutch the stationary worm-plate to the rotating clutch member Whenthelatter is moving at a high rate of speed, and hence the object of the present invention is to provide means in a clutch of the character described for first friotionally engaging the Worm-plate with the rotating clutch member and to thereafter posi tively engage it with said members when said plate has reached; a fairly high speed, so as to lessen the shock incident to the positive` engagement of the two parts.

Referring to the accompanying drawings,

Figure 1 represents a longitudinal section through a clutch embodying the present improvements. Fig. 2 the line 2 2 of Figl. Fig. 3 represents in perspective View the centrifugally-aeting dog or pawl and the part upon which it is mounted. Fig. 4 represents a section on the line 4 4 of Fig. 2.

moved.- Fig. 6 represents the shifting lever and the appliance for frictionally engaging the worm-plate to hold it against rotation to nnclutch the movable shoes. Fig. 7 represents a detail of Fig. 2 showing one of the n a o `member 14.

represents a section onf Fig. 5 represents, on a reduced scale, the oppositely-moving shoes and the mechanism actuated by the Worm-plate, thisview being taken with the worm-platere# locking-pawls in the opposite or unlocked position. Fig. S is a section online 8 S of Fig. '7.

Referring to said drawings, the drivingshaft 10 and the driven shaft 1l are in axial alinement, as shown. To the shaft 10 is rigidly secured the rotating clutch member, illustrated as a wheel 12, With a flanged rim 13. To the said rim is rigidly secured an inwardly-projecting flange 131,'having a'beveled friction-surface 132. The saidA Iiange constitutes Van internal ratchet, being provided with the diametrically opposite teeth (See Fig. 2.) Within the rim of the wheel12 is placed the clutch member 14, keyed to theshaft 11. This clutch member carries the separable shoes 15 16, whose outer edges rare adapted to make Contact with the inner surface of the rim 13. The shoe 15 has the arms 1717,'in which are fulcrumed two levers 19 19. The free ends of said levers bear against the shoe 16, their inner ends bearing against nuts21 21 on a screw-shaft22. The arms 17 and the levers 19 are formed and re1- atively arranged substantially as in the Patent No. 686,923, abovelreferred to'. Springs .2O 2O connect the shoes 1516as shown. The

screw-shaftf22 carries a Worm-Wheel 24, With which' is engaged the worm in the form of a spiralscroll 25 on the scroll-plate 26. This scroll-plate is formed on the end of a sleeve 261 and is loosely mounted on the hub of the Keyed upon the hub or sleeve 261 of the Worm there is Aa sliding member 30. This member is provided at one end With a Vflange 31,'beveled oomplementally to the friction-surface 132 ofthe member 12.

The said member SOis therefore adapted to be moved into frictional engagement with the rotating .clutch member 13, so as to frictionally drive the Worm and cause it to rotate the Worm- Wheel,and thereby force the shoes 15 1G into frictional engagement With the interior surface of the rim 13fof the clutch member 12.

For the purpose of locking the sliding member30 with the clutch member 12 I provide centrifugally-acting pawls ordogs,Whi'ch are ind- `cated at 32. lThese dogs are each fulcrumed at one end upon a stud 33, securedin the member 30, and they are normally held in Aan inoperative position, resting against a pin 34,

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tion; but when the speed of the member 30V exceeds a certain number of revolutions per minute the longer ends of the dogs are thrown outward by centrifugal actiony and are caused Vto engage the ratchet-teeth 133 of the rotating clutch member 12, whereupon the said members 30 and l2 are positively clutched together and are rotated in unison. This positive clutching of the two members causes the positive rotation of the worm and the worm-wheel until the shafts 11 and 10 are so firmly clutched together as to move in unison. In order to unclutch the parts, it is merely necessary to disengage the member 30 from the rotating clutch member 12 and to apply friction to the said member 30. To accomplish this, I provide the following mechanism: On the hub of the'said member 30 is a circumferential flange 40. A yoke 41 is formed with pins 42 42, which lie at either side of the said flange, as shown in Fig. 1. The upper end of the yoke is pivoted by a pintle 43 to a spindle 44, adapted to slide in a tubular guide 4 5, attached to some convenient stationary support. The spindle is formed on its end witha head 46, between which and a shoulder 47 on the guide there is placed an expansion helical spring 48. By reason of the jointed connection between the yoke and the spindle 44 the said yoke may be swung in the direction ofthe axis of the shaft 11 to move the member 30 intoand out ofoperative position with respect to the member 12. The yoke is formed with two friction-shoes, (indicated, respectively, at 50 and 51,) being diametrically opposed to each other. The shoe 5l is rigidly secured to the tQp portion of the yoke, while the shoe 50 is mounted upon the end of a screw-bar 52, passed upward through a threaded portion in the yoke and formed with ythe handle 53, by whichit may be rotated. The said screw-bar has a head 54, arranged in a socket in the shoe, and a disk 55, through which the screw-bar passes, is secured to the said friction-shoe 50. The said shoe is grooved, so as to take over the iiange 40, so that when the screw-bar 52 is rotated the shoe 50 will be held against rotation.

The parts are so arranged and constructed that when the yoke is moved to disengage the member 30 from the member 12 the screwbar 52 may be rotated to cause the frictionshoes 50 and 51 to frictionally engage the periphery of the flange 40 and hold the member 30, and thereby the Worm 26, against rota? tion. The provision of the spring 48 enables the friction-shoes 50 and 5l to engage the flange 40 of the member 30, as will be readily understood.

Having thus explained the nature of the invention and described a way of constructing and using the same, although without attempting to set forth all of the'formsin 'which it may be made or all of the modes of its use, I declare that what I claim is- 1. In a friction-clutch, a normally rotating clutch member having two friction-surfaces, a member having friction mechanism to engage one of said surfaces, a worm for actuating said mechanism, and a member in sliding engagement with said worm, and provided with means for frictionally engaging the other surface of the normally rotating clutch member, and with speed-controlled positive clutching means for engaging said normally rotating clutch member.

2. In a friction-clutch, a normally rotating clutch member having a friction-surface, a member having a complemental friction-surface to engage the first-mentioned frictionsurface and having a movable positive clutching device operative by centrifugal action to positively engage the first-mentioned clutch member when the second-mentioned member reaches a predetermined speed of rotation, said normally rotating clutch member having means to be engaged by said positive clutching device.

31 In a clutch, a normally rotating clutch member having a friction-surface, and one or more ratchet-teeth, and a member adapted to frictionally engage the said friction-surface, said member being provided with a pawl operative by centrifugal action when the said second member reaches a predetermined speed of rotation to engage the tooth or teeth on the said normally rotating clutch member.

4. In a friction-clutch, a normally rotating clutch member having two friction-surfaces, a member having relatively movable frictionshoes to engage one of the friction-surfaces, means for actuating said shoes including a worm rotatable independently of the shoecarrying member, and a third member rotatable with the second-mentioned member, but adapted to slide thereon, the said third m ember having means for .frictionally engaging the first-mentioned member, and speedcontrolled means for positively engaging the first-mentioned member.

5. In a friction-clutch, a normally rotating clutch member having a friction-surface, a second member having relatively movable friction-shoes to engage the friction-surface of the first-mentioned member, means for actuating said shoes, including a worm rotatable independently of the shoe-carrying member, a third member for connecting the worm to and disconnecting it from the first-mentioned normally rotating clutch member, and a yieldingly-mounted shifting lever having friction mechanism for retarding the rotation of the said third member, whereby the relative movement of said worm mechanism is reversed and the friction-surfaces separated.

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6. In afriction-clutch, a normally rotating l and means for effecting the engagement of I clutch member, a second member having frie tion mechanism for engaging the rst-mentioned member, a third member for operating the friction mechanism, and means for retarding the rotation of the said third member for reversing the operation thereof, said retarding means including` a yieldingly-mounted shifting lever, friction-shoes on said lever,

said shoes With said third member.

In testimony whereof I have afxed my signature in presence of two witnesses.

MALCOLM CAMPBELL.

Witnesses:

M. B. MAY, C. C. STECHER. 

